The bowhead whale (Balaena mysticetus) is a baleen whale of the right whale family Balaenidae. A stocky dark-colored whale without a dorsal fin, it can grow to 20 m (66 ft) in length. This thick-bodied species can weigh 75 tonnes (74 long tons; 83 short tons) to 100 tonnes (98 long tons; 110 short tons), second only in mass to the blue whale, although the bowhead’s maximum length is less than that of several other great whales. It lives entirely in the nutrient rich Arctic and sub-Arctic waters; unlike other whales that migrate to feed or reproduce in low latitude waters. It is also known as Greenland right whale or Arctic whale. American whalemen called it the Steeple-top, Polar whale, or Russia or Russian whale. The bowhead has the largest mouth of any animal and is perhaps the longest-living mammal.

Bowheads were once thought to live 60 to 70 years, similar to other whales, however, discoveries of 19th century ivory, slate and jade spear points in freshly killed whales in 1993, 1995, 1999, and 2007 triggered research based on structures in the whale’s eye, suggesting that at least some individuals reached 150–200 years old. The amino acid racemization process has provided the scientific basis for these claims, although this process is controversial and has failed to correlate well with other dating methods.

In May 2007, a 50 tonnes (49 long tons; 55 short tons) specimen caught off the Alaskan coast was discovered with the head of an explosive harpoon embedded deep beneath its neck blubber. The 3.5 inches (89 mm) arrow-shaped projectile was manufactured around 1890 in New Bedford, Massachusetts, a major whaling center, suggesting the animal may have survived a similar hunt more than a century ago.